Using excel solver, solve the following LP problem.

x1=number of cases of model A made

x2= number of cases of model B made

x3= number of cases of model C made

x4= number of cases of model D made

Min cost (Z) = 10 x1+8 x2+14 x3 +10 x4

Subject to

1x1+1x4110 Demand model A

1x2+1x3150 Demand model B

4x1+4x2600 Molding time

6x1+8x31100 Assembly time

x1,x2,x3,x40 (Non-negativity constraint)

Note that fractional values for the models are acceptable. Use two decimal places to provide answers to questions 1 through 4

1. What is the optimal solution? What is the value of the objective function?

2. Suppose that the cost for the model B is increased by $1 per unit, and the cost for the model C is increased by 2 per unit. What will be the new optimal solution be?

3. What is the value of reduced cost for the model A? Explain it in not more than four sentences. Provide any calculation to support your point.

3. If the assembly time is 1080 units instead of 1100 units, what is the new cost? and Identify the range of optimality for the objective function coefficients.